Despite a stellar 2011 season (77 tackles, 5 forced fumbles, 4 recovered fumbles, 2 interceptions and 2 punt return touchdowns) in which he went on to be a Consensus All-American and Heisman Trophy finalist, Mathieu came into the draft with a bit of a checkered past.

Before the 2012 season, the "Honey Badger" was kicked off the LSU football team for a violation of team rules related to repeated failed drug tests.

Still, the Cardinals believed Mathieu, who hasn't played competitive football in over a year, could be an instant contributor under the right guidance. And it doesn't look like Steve Keim and Co. will have to look far in the guidance department.

Two-time Pro Bowl cornerback Patrick Peterson was Mathieu's teammate at LSU in 2010 and said he was beyond excited by Friday's news.

"Honestly, this is by far one of the happiest days of my life," Peterson said in a conference call. "It feels like I got drafted again when I saw his name pop up across the board. For him to have another opportunity to do what he loves is unbelievable.

"Going back seven months ago, he said his dream was to play with me once again no matter how it came. He said that was definitely his dream and his dream came true."

It's a dream that came to fruition likely in part because of the advice Peterson shared with the Cardinals' front office.

"They did talk to me throughout the process trying to figure out what kind of kid he was and how he was as a teammate," said Peterson. "I told them, 'I'm willing to put my neck on the line for the kid. I promise he'll walk a straight line and arrow. He won't give you any problems.'"

Peterson, who worked out with his former teammate in the Valley leading up to the NFL Draft, admitted that he wants to see the defensive standout succeed with the Cardinals and will do what it takes to help make the transition process easier.

"I was asked if I'd continue being his mentor," said Peterson. "It's something I'd love to do, as well. And, it's something he wants me to do as well, just to continue to guide him."